Eco-evolutionary dynamics in the Anthropocene

Species are being adversely affected by chronic and acute environmental changes with consequences including increased disease outbreaks and mass mortality. These impacts are mediated in part by physiological tolerances and life-history traits that may reflect underlying genetic differences; the genetic differences may amplify or mute a species’ sensitivity to change. As extreme disturbances are projected to increase in both frequency and intensity a population’s capacity to respond either with epigenetic mechanisms or with standing genetic variation will become increasingly important for acclimation or rapid adaptation to the changing environment or risk extinction. Although microevolutionary responses to extreme events are likely to be widespread, capturing the appropriate genetic and ecological data to document such phenomena in natural populations remains limiting. My goal is to understand risk factors and potential responses to spatial and temporal natural and anthropogenic change. My work captures multiple facets of these topics by coupling ecological and genetic analyses through 3 main themes.

(1) Building a multi-year ecological and genetic monitoring framework
(2) Addressing fundamental questions using ecological genetics
(3) Incorporating ecological genomic insights into conservation actions

Below are the current projects on which I’m working.

Selection and genetic succession in the intertidal – population genomics of Pisaster ochraceus during a wasting disease outbreak and its aftermathPisasterAdult_Cropped
The 2013 sea star wasting disease (SSWD) pandemic in Pisaster ochraceus provided a rare opportunity to disentangle the dynamic interaction between natural selection, dispersal, and extreme conditions. With samples bracketing the mass mortality I am exploring the genetic consequences of the event, trajectory of recovery in survivors and offspring, and implications for future events.

Collaborators: Mike Dawson (UC Merced), Ian Hewson (Cornell), Pete Raimondi (UC Santa Cruz), & John Wares (U. Georgia, Athens)

2017 Update:

Understanding the Sunflower Sea Star’s Genomic Risk, and Potential for Genetic Rescue, from Sea Star Wasting Disease: Applying Genomic Resources to Improve Captive Breeding and Ecosystem Restoration
The sunflower sea star was particularly hard hit by wasting disease. This project aims to discover genomic variation in the sunflower sea star that confers resilience to SSWD and other stressors and will provide a far Pycnofuller understanding of the genomic factors that shaped the high risk of sunflower sea stars to SSWD in 2013/2014, and the consequences of that event on remnant patterns of genomic diversity. The goal is to generate genomic insight that could be applied to shape a captive breeding program that advances genomic resilience in the new population.

Collaborators: Mike Dawson (UC Merced)

Ecological genetics of Leptasterias sp.Lept
Leptasterias sp. was also affected by SSWD. With a stark contrast in life history to the high gene flow spawning P. ochraceus, Leptasterias broods its offspring to a crawl away phase and has low dispersal potential. I aim to explore the genomic differences and similarities between these two species (and others) spanning the SSWD episode.

Exploring genomic signals of convergent vs. parallel evolution associated with environmentally-mediated selection in the eelgrass, Zostera marina, from local to global scales
Using whole genome resequencing we intensively sampled two bays along an environmental gradient to document intra- and inter-bay populationIMG_9040 genetic structure and identify putative temperature-associated loci. Next, we interrogated our rangewide Z. marina dataset for these loci and others indicated across parallel latitudes. 

Collaborators: Rachael Bay, Rick Grosberg, Jay Stachowicz (UC Davis)